This invention is related in general to networks and more specifically to systems and methods for observing or measuring network performance or communications link quality.
Systems for observing communications link quality are employed in various demanding applications including power-control systems for cellular networks and problem-diagnosis systems for Voice Over Internet Protocol (VOIP) communications sessions. Such applications often demand accurate network-quality observation systems that facilitate determining where and when communications link quality has degraded.
Network-quality observation systems are particularly important in VOIP applications, where a given communication session may employ plural types of networks, including wireless and wired networks, each with different performance characteristics. An exemplary VOIP system includes a first endpoint and a second endpoint, such as a wireless VOIP phone and a wired VOIP phone, respectively. In this example, a wireless Access Point (AP) interfaces the wireless VOIP phone with the Internet. An Internet-based soft switch facilitates routing one or more calls between the first endpoint and the second endpoint over the Internet. Accordingly, a given telephone call may employ wireless and wired portions of a network between the VOIP endpoints.
In VOIP applications, the quality of a given phone call is often assigned a Mean Opinion Score—Listening Quality (MOS-lq). The MOS-lq score is affected by packet losses occurring over the communications link between the endpoints as reported by one or more of the endpoints. Unfortunately, conventional systems and methods for determining and handling MOS-lq scores do not adequately facilitate determining where degradation of the MOS-lq score occurs in the overall network.